1. Field of Invention
The present disclosure of invention relates to a backlight assembly and a method of driving the same. More particularly, the present disclosure relates to a backlight assembly capable of performing a local dimming and a method of driving the backlight assembly.
2. Description of Related Technology
In general, a liquid crystal display (LCD) includes a liquid crystal display panel to display an image and a backlight assembly to supply a light to the liquid crystal display panel from a back side of the LCD panel. The backlight assembly may employ one or more cold cathode fluorescent lamps as its light source or other sources such a light emitting diodes (LEDs).
In order to increase a contrast ratio of a displayed image or reduce power consumption of the backlight assembly, recently various selective dimming methods have been applied to the liquid crystal display to control brightness of the backlight assembly.
As one of the dimming methods, a local dimming method sets dimming areas of a display panel, calculates gray-scale values of images respectively displayed in the dimming areas, and controls brightness of light emitted from the backlight assembly for those dimming areas according to the calculated gray-scale values. In the local dimming method, the backlight assembly increases the brightness of light supplied to areas in which the gray-scale value is relatively high and decreases the brightness of light supplied to areas in which the gray-scale value is relatively low.
The backlight assembly to which the local dimming method is applied is divided into a plurality of light generating blocks and includes a plurality of driving units that control the brightness of light emitted from each light generating block for its respective dimming area. However, if plural light generating blocks are connected to a specific driving unit and the plural light generating blocks are simultaneously brightened in concentrated fashion, overheating may occur in the specific driving unit, so that long term reliability of the specific driving unit is lowered. In addition, the specific driving unit may not be able to supply all the power that is needed to simultaneously brighten all the light generating blocks to a prespecified maximum brightness level when so needed according to a prespecified dimming method to boost the brightness of light emitted from the light generating blocks.